1. Field of the Invention
The present invention relates to a lens apparatus having a function of sending (transmitting) optical aberration data to a camera, and to a camera system including the lens apparatus.
2. Description of the Related Art
Various lenses including interchangeable lenses have optical aberrations such as longitudinal chromatic aberration, chromatic aberration of magnification and distortion. These optical aberrations cause deterioration of an image captured by a camera such as color blur and distortion.
Japanese Patent Laid-Open No. 2006-135805 discloses an aberration correction method in which optical aberration data of an interchangeable lens for each zoom position, each focus position and each iris (aperture stop) position are stored in a camera to which the interchangeable lens is attached and the camera performs aberration correction of an image using the optical aberration data.
However, the method disclosed in Japanese Patent Laid-Open No. 2006-135805 in which the camera stores the optical aberration data of the attached interchangeable lens requires, when a different interchangeable lens is attached to the camera, rewriting of the optical aberration data stored in the camera or adding of new optical aberration data of the different interchangeable lens to the camera by a user.
In order to eliminate such a complex data rewriting or adding process, the following method may be used. Each of plural interchangeable lenses itself stores its optical aberration data. Then, in response to power-on of a camera to which one of the interchangeable lenses is attached, the attached interchangeable lens sends its optical aberration data to the camera, and the camera stores the received optical aberration data to use it for aberration correction.
However, such a method requires transmission of a large amount of the optical aberration data from the interchangeable lens to the camera. Therefore, it takes a long time until the transmission of all the optical aberration data is completed to enable the camera to start the aberration correction. This prevents capturing of aberration-corrected images for a long time after power-on of the camera, which may miss an image capturing chance.
Moreover, a lot of interchangeable lenses can use plural accessories such as a wide converter, a filter and an extender, and these accessories also have optical aberrations. Therefore, when the interchangeable lens with which the accessory is used is attached to the camera, optical aberration data of the accessory should be sent from the interchangeable lens to the camera. Thereby, the optical aberration data to be sent from the interchangeable lens to the camera increases more and more, which makes the time required for data sending longer.